Lol, a lot trial & error, countless deadly strike widgets, and some less-used funtions like the Target widget. The great thing about Magic Dosbox is that if you’re missing a certain feature, you can just ask for it and it will be implemented if it’s somehow possible. And there are already so many functions, you can achieve almost anything with a little creativity.
After I had built this, and the Age of Empires & Ultima V layouts, layers were implemented. So if I had to create these layouts again from scratch, it would be much easier, and would require far less deadly strike widgets to show & hide all the icons.
What I do when I see an interesting layout is, I sort of reverse engineer them: import, launch, enter edit more, and take a look at every widget to see what it does.